1. Field of the Invention
The present invention is related to ground anchors. More particularly, the present invention is related to anchors driven into the ground to remain in the position thus established with minimal slippage.
2. Discussion of Related Art
In my published U.K. Patent Application 2 085 386 A there is described a ground anchoring system in which a generally flat anchor plate is secured to one end of a flexible anchor line and driven edge-first into the ground by a driving tool.
When the driving tool is removed and a lifting force is subsequently applied to the flexible line, the plate tends to skew across the hole and thereby resist extraction from the ground. A somewhat similar device is disclosed in U.S. Pat. No. 4,003,169.
On the whole this system works satisfactorily, but I have found that there is often a significant delay before the plate is skewed after a lifting force is applied to the line. During this period, the plate can be pulled some distance back up the hole, and the anchored object may not then be firmly anchored in its desired position. This problem is particularly troublesome when anchoring objects to the river or sea bed. For example, when anchoring a frond mat to the sea bed to combat erosion of the bed beneath structures such as oil or gas pipelines, any "lifting" of the mat after it has been anchoed can seriously affect subsequent performance of the mat under operating conditions.